Skimmer lines suck air, main drain fine

[dzl13]

I have a simple Jandy valve splitting the main drain from 2 joined skimmers. When I switch to 100% main drain then it pulls fin, no air in the lines, when I switch to split or 100% skimmers it will hold for a second but then it looks like the air "breaks" into the pump basket. I say breaks because you can feel the pressure pulse come through. IT will generally plug off and start to cycle out the air and then it comes back. It seems like if it goes above a certain line pressure it will suck air. Because of this I cannot vacuum or use the skimmers at all. Any suggestions or redirection are most appreciated.

1.5" suction/return lines
Pentair 348023 SuperFlo Energy Efficient 1HP Single Speed Pool Pump, 115V/230V
Hyaward DE filter
25000 gal gunnite with 2014 replaster
2 skimmers and 2 inlets

 

[JohnT]

Welcome to TFP!

Is the water level at the full mark on the skimmer faceplate? Does the weir door in the skimmer move up and down freely?

 

[Kiss4aFrog]

Welcome to the forum

The water level should be at least 1/3 of the way up the skimmer to keep it from sucking air. Like JohnT said, also check the doors to make sure they are floating freely with the level of the water.

 

[dzl13]

Welcome to the forum

The water level should be at least 1/3 of the way up the skimmer to keep it from sucking air. Like JohnT said, also check the doors to make sure they are floating freely with the level of the water.

My skimmers do not have weir doors but the air in the line issue exists regardless of the water level.

 

[Kiss4aFrog]

Can you please add your pools info into your "signature" as outlined here :lookhere: http://www.troublefreepool.com/content/165-getting-started

Have you watched the skimmers to see if possibly there is so much suction with the main drain closed they are creating a vortex inside the skimmer and sucking in air ??
Are your skimmers missing the doors or are they designed without them ?? Seems without doors they wouldn't be as effective at tapping debris.

If the skimmers aren't sucking in air it sounds like you have a leak in the skimmer lines. Some info on troubleshooting :lookhere: http://www.troublefreepool.com/content/150-leak-detection

 

[dzl13]

Can you please add your pools info into your "signature" as outlined here :lookhere: http://www.troublefreepool.com/content/165-getting-started

Have you watched the skimmers to see if possibly there is so much suction with the main drain closed they are creating a vortex inside the skimmer and sucking in air ??
Are your skimmers missing the doors or are they designed without them ?? Seems without doors they wouldn't be as effective at tapping debris.

If the skimmers aren't sucking in air it sounds like you have a leak in the skimmer lines. Some info on troubleshooting :lookhere: http://www.troublefreepool.com/content/150-leak-detection

Thanks for the suggestion. I had checked for the vortex effect but the suction is not great, the actual suction line is very deep (12" below the water line), and with the catch basket in place there isn't any noticeable vortex.

Aside from spending $350+ on someone to simply locate the leak (and not even fix it) are there any short cuts?

 

[duraleigh]

Your description is a little hard for me to follow but you must find the source of the air that is being sucked INTO you system. Without air being sucked into your system, the conditions described in your first post will not happen.

I am sure it is something simple but I cannot get a good mental picture of where the air is getting in.

 

[Bama Rambler]

Have you checked all the lines and connections above ground? Even the 3-way valve that divides the skimmer & MD? Believe it or not, it could leak one way and not the other.

It may also help if you could post a pic of the layout.

 

[dzl13]

I have checked all above ground. As you can see form the pic below my setup is simple. There are 2 suction lines coming through the concrete, the left is the skimmer line (both skimmers are tied together somewhere underground) and the right is the main drain connected via a 3 way jandy. I can find no air leaks in this plumbing (sealed it as best I could with water and plastic wrap and duct tape). Is it possible that the jandy is bad? could it suck air on one side and not the other? IS there a way to check before replacing it? I couldn't see a way an oring would fail and still seal on side. Much appreciated.

 

[Bama Rambler]

With that setup it's most likely not the valve. Did you run water over all the fittings while it was set to skimmer only and the pump running to see if the air slowed or stopped?

If so it may be time to call the leak detectors or start digging.